79 cordoba elect problem
 

79 Cordoba 360 Elect problem
Over winter car sat with charger attached and charging once a month. Did not charge for about three months and in March it would not start I used a 50 amp jump charge to start it started after a bit but then the power ant. quit and the radio will not play with lights on. I changed radio and new one will not play unless lights are on wierd right.
So I investigated and under hood on firewall ballast resistor is hot enough to burn your finger if touched.
What shorted out any clue on what happened?
*